Laminated plastic yarns and method and apparatus for making the same



May 26, 1970 J. NETSEL LAMINATED PLASTIC YARNS AND METHOD AND APPARATUSFOR MAKING THE SAME 2 Sheets-Sheet 1 Original Filed Feb. 19, 1965 Q JM QR R g R N wm wm m.

MOE

INVENTOR. JOSEPH NETSEL A TTORNE Y.

y 6, 1970 J. NETSEL 3,514,368

LAMINATED PLASTIC YARNS AND METHOD AND APPARATUS FOR MAKING THE SAMEOriginal Filed Feb. 19, 1965 2 Sheets-Sheet 2 INVENTOR.

JOSEPH NETSEL no.9 BY

ATTORNEY:

United States Patent 3,514,368 LAMINATED PLASTIC YARNS AND METHOD ANDAPPARATUS FOR MAKING THE SAME Joseph Netsel, Providence, R.I., assignorto Acme Backing Corporation, Stamford, Conn., a corporation of New YorkContinuation of application Ser. No. 433,983, Feb. 19,

1965. This application Mar. 27, 1968, Ser. No. 716,666 Int. Cl. D02g3/00 US. Cl. 161-177 12 Claims ABSTRACT OF THE DISCLOSURE A laminatedplastic yarn formed from film having longitudinal prescored fold linesto insure in the folded yarn precise, uniform width and thickness of theyarn throughout the length thereof; together with a method and apparatusfor forming the same.

This application is a continuation of applicants copending applicationSer. No. 433,983 filed Feb. 19, 1965, now abandoned.

Conventional plastic yarns of the laminated type, which are formed byfolding the opposite lateral portions toward each other over a centralportion, have a tendency to vary in width along the length thereof andmay also vary in thickness at various points along the length thereof,due to changes in the disposition of the individual laminae of the yarn.

Such irregularities in conventional plastic yarns not only interferewith the usual textile weaving and finishing operations in convertingsuch yarns into fabric, but necessarily require special techniques andadjustments in the manufacture of fabrics utilizing such yarns. Alsotextile fabric designs are compelled to recognize the shortcomings ofthis type of fiat yarns and must compensate for the same.

Accordingly, an object of this invention is to provide an improvedmulti-ply flat plastic yarn having a precise Z fold construction whichinsures uniformity of width of the yarn throughout its length, as wellas uniformity of ply disposition and thickness.

Still another object of this invention is to provide an improved methodand apparatus for converting plastic film of a selected gauge intomultiply yarns which have a precise uniform width and thicknessthroughout the length thereof.

Yet another object of this invention is to provide an improved fiatmonofilament textile yarn of superior tensile strength with a lowspecific gravity, which lends itself to the manufacture of a variety oftypes of fabric and particularly as warp elements in drapery fabrics andthe like.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

In the drawing:

FIG. 1 is a plan view showing the progressive conversion of plastic webinto yarns embodying the invention;

FIG. 2 is a side elevational view showing the apparatus and procedureembodying the invention;

FIG. 3 is a front elevational view showing the slitterscoring assemblyof said apparatus;

FIG. 4 is an end elevational view thereof;

FIG. 5 is an enlarged sectional view showing the meshingslitting-scoring discs;

FIG. 6 is an enlarged sectional view showing the slit and scored stripissuing from said assembly;

FIG. 7 is a side elevational view of the folder of said apparatus;

FIG. 8 is an end view thereof; and

FIG. 9 is a transverse sectional view showing the finished yarnembodying the invention.

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Essentially, the yarn of the instant invention is derived from athermoplastic film or web of selected gauge and width, which isprocessed in a continuous manner by slitting the same into laterallyrelated strips, simultaneously scoring the strips, folding the scoredstrips by a Z fold into a three-ply laminate, which is then heated,stretched and tensilized to form the finished yarn of precise uniformwidth and thickness.

Thus, as shown in FIG. 1, 10 designates a plastic film or web ofselected gauge and width, preferably derived from a polyolefin resinsuch as polypropylene. Film 10 is continuously slit along parallel lines11 to form laterally related individual strips 12 which aresimultaneously scored longitudinally along a pair of parallel, equallyspaced longitudinal lines 13.

Strip 12 having two score lines 13 allow the same to be folded in Zfashion to form a 3-ply laminate indicated at 14. The laminated strip 14is then stretched at a controlled temperature, reducing the strip to aselected width and thickness and converted to the final multi-plymonofilament yarn 15.

As indicated in FIG. 2, yarns 15 may be produced in a continuous manner,from thermoplastic film or web 10 of selected gauge which is provided ona reel 16 suitably mounted on a horizontal axis for movement in alongitudinal path through successive processing elements. Thus, the film10 is fed from reel 16 to tensioning means 17 comprising a pair ofopposed felt members 18, 19, where one of said members is held in afixed horizontal position and the other member is mounted for adjustedmovement toward the fixed member to thereby vary the tensioning actionon the film moving between said tension members 18, 19.

The tensioned plastic film then passes to a web guide comprising a pairof vertically disposed plates 20 adjustably mounted in spaced relationon a guide bar 21, to engage the side edges of said film or web 10 todirect the same in a given path around a guide roller 22 and thence to aslitting and scoring roller assembly 23, hereinafter described indetail, where the film 10 is slit to form strips 12 and simultaneouslyscored to form score lines 13 therein.

The leading ends of strips 12 are hand folded in a Z fashion along saidscore lines 13 and introduced into folder means 24 where the foldingoperation thereafter takes place in a continuous manner. The foldedstrips 14 issuing from folder 24 are moved by driven pull rollers 25operating at a surface speed slightly greater than the surface speed ofthe slitter-scorer roller assembly 23.

From the pull rollers 25, the strips 14 pass over a heated platen 26 ata temperature of about 235 F., the strips having moving surface contactwith said platen. The heated strips then pass to a second set of pullrollers 27 which have a surface speed which is 400% to 725% greater thanthat of puller rollers v25, whereby the strips 14 are stretched andreduced in width and thickness to selected dimensions to form the yarns15.

The yarns 15 then pass through chamber 28 heated by forced hot air at atemperature of about -185 F., by way of a guide roller 29 in saidchamber, to pull rollers 30 which have a surface speed of about 2% lessthan that of pull rollers 27 to allow the yarns to recover before thesame are wound on bobbins, reels, pirns, or the like, not shown.

The slitter-scorer assembly 23, as shown in FIGS. 3-5, is adapted toslit film 10 continuously into strips 12, which strips aresimultaneously scored to provide score lines 13 which permit the strips12 to be folded in Z form. Accordingly assembly 23 comprises a pair ofparallel, horizontally disposed shafts 31, 32 arranged to be driven, bymeans not shown. On the shafts 31, 3-2 are mounted a series of spacedslitting and scoring discs in meshing relation adapted to slit film atequally spaced intervals along the width thereof and to simultaneouslyscore the slit web portions at equally spaced transverse intervals todivide each of said strips into a pair of outer zones and anintermediate zone, all of equal width.

To this end, there is mounted on the left hand end of the upper shaft31, a square edge slitter disc 33, followed by spacer discs 34 of equalwidth and alternating with either bevel edge slitter-scorer discs 35 orsquare edge slitter-scorer discs 36 in a predetermined sequence.Similarly, on the lower shaft 32 there is mounted on the left hand endthereof, a square edge slitter-scorer disc 37, followed by spacer discs34 which alternate with bevel edge slitter-scorer discs 38 similar todiscs 35 or additional square edge slitter-scorer discs 37 similar todiscs 36 and terminating at the right hand end thereof with a squareedge slitter disc 39.

Each of the discs 35, 38 is bevelled at one edge 40, 41, respectively,at an angle of about while the other edges 42, 43 respectively are leftin squared condition. The bevel edges 40, 41 have a width of about .003"on the face edge of discs 35, 38 and a depth of about .010 on the oneside thereof. The discs 35, 36 on shaft 31 intermesh with discs 37, 38on shaft 32 to an extent determined by the gauge of the web 10 passingtherethrough. By way of example, the discs may mesh to an extent ofabout .010" to allow for slitting and scoring the film 10.

It will be apparent from a consideration of FIG. 5 that discs 35, 36, 37and 38 are arranged in successive assemblies along shafts 31, 32 so thatcoacting square edges will effect a slitting action while a square edgecoacting with a bevel edge through a small clearance therebetween willeffect a scoring action, which is limited to about /3 to /2 thethickness of the film 10. Thus, starting at the left hand end of shafts31, 32, discs 33, 37 coact to slit and trim the left hand edge of web10; the square edge of disc 37 and bevelled edge 40 of disc 35 form afirst score line 13A on one side of the film 10 and the square edge 42of disc 35 and the beveled edge 41 of disc 38 form the second score line13B on the other side of film 10. The square edge of disc 38 and thesquare edge of disc 36 slit the web 10* to thus provide the first scoredstrip 12. The square edge of said disc 36 and the adjacent bevel edge 41of adjacent disc 37 again forms a score line in the next strip 12 andthis is repeated throughout the width of web 10 with successive slittingactions and intermediate scoring effects, until the square edge of thelast disc 35 on shaft 31 coacts with the square edge of disc 39 on shaft32 to slit and trim the right hand side edge of web 10.

Obviously, the width of spacer discs 34 will determine the spacingbetween score lines 13. As the slit and scored strips 12 issue fromassembly 23, said strips will be preconditioned by score lines 13A, 13B,FIG. 6 to facilitate a Z fold of lateral zone A toward one side ofintermediate zone B while the other lateral zone C is folded toward theother side of intermediate zone B, which folding action takes place in acontinuous manner in folding means 24.

As shown in FIGS. 8, 9, said folding means comprises a pair of opposedplates 50, 51 held together by bolts 52. The lower plate 51 is formedwith a shallow recess 53 on its upper surface, thereby providing athrough slot 54 between plates 50, 51 extending between the front andrear edges thereof. Slot 54 is of a depth to pass the three-ply strip 14as the same passes from assembly 23, and to bring zones A, C intointimate fiat contact with intermediate zone B thereof. The forwardedges of plates 50, 51 may be slightly beveled at slot 54 to facilitatethe entry of strips 14 therein. The depth of slot 54 may be about 50%greater than the thickness of entering strip 14. The surfaces formingslot 54 should be highly polished.

The film 10, when formed of polypropylene, may be processed at speeds ofup to 5060 yards per minute, and platen temperatures of 230 to 240 F.,preferably 235 F. were found to be effective in producing a desirableflat yarn 15. The web 10 may have a gauge of .0015" but such gauge maybe .001" or greater.

While the process herein disclosed is particularly effective when usingfilms or webs of polypropylene, it is understood that other plasticfilms derived from polyethylene poly vinyl chloride, polystyrene, etc.may be similarly slit, scored and Z folded to form multiply yarns ofuniform width and thickness. Platen temperatures would be adjusted inaccordance with the resin used.

By way of illustration, strips 14 may have a width of about .062" andupon stretch yarns 15 may have a reduced width of about .028".

As various changes might be made in the embodiments of the inventionherein disclosed without departing from the spirit thereof, it isunderstood that all matter herein shown or described shall be deemedillustrative and not limiting except as set forth in the appendedclaims.

What is claimed is:

1. A flat, multi-ply plastic monofilament yarn comprising a stripprescored along spaced longitudinal lines to provide a longitudinallyextending intermediate portion and a lateral portion on each side ofsaid intermediate portion, said portions being of substantially equalwidth, one of said later portions being folded on one of said scorelines into contact with one surface of said intermediate portion, theother of said lateral portions being folded on another of said scorelines into contact with the other surface of said intermediate portion,said yarn being of uniform width and uniform thickness throughout thelength thereof.

2. A multi-ply yarn as in claim 1 wherein said plastic is polypropylene.

' 3. A three ply flat yarn formed from a folded plastic strip having a Zfold cross section with the free longitudinal edge of one outer plysubstantially extending to one folded edge of the intermediate ply andthe free longitudinal edge of the other outer ply substantiallyextending to the other folded edge of said intermediate ply, said yarnbeing of uniform width between the free edges of said outer pliesthroughout the length thereof.

4. A flat yarn as in claim 3 wherein said strip is prescored along linesat the juncture of the opposite edges of said intermediate ply with saidouter plies.

5. A flat yarn as in claim 4 wherein said prescore lines arerespectively on opposite sides of said strip.

6. A method of forming multi-ply flat yarns comprising slitting aplastic film into a plurality of strips, scoring each strip alongtransversely and equally spaced longitudinal lines to provide anintermediate portion therein and lateral portions on either side of saidintermediate portion, folding the lateral portions of each strip alongsaid score lines respectively into contact with opposite sides of saidintermediate portion, heating said folded strips and longitudinallystretching the folded, heated strip.

7. A method as in claim 6 wherein said plastic film is polypropylene andsaid folded strips are heated to a temperature of about 235 F.

8. A method as in claim 7 wherein said heated folded strip is stretchedfrom about 400% to about 725%.

9. A method as in claim 6 wherein said slitting and scoring operationsare simultaneous.

10. A method of forming flat yarns comprising scoring a thin strip ofplastic material along a pair of transversely spaced longitudinal linestherein to provide a longitudinally extending intermediate portion and apair of longitudinally extending lateral portions respectively on eitherside of said intermediate portion, folding the lateral portions of saidstrip along said score lines respectively into contact with oppositesides of said intermediate portion, heating said folded strip andlongitudinally stretching the folded, heated strip.

11. Apparatus for forming multi-ply flat yarns from a thin film ofthermoplastic resin comprising means for slitting said film into aplurality of strips, means for scoring each strip longitudinally along apair of parallel lines respectively on opposite sides thereof, means forfolding each strip along the score lines thereof to bring longitudinallyextending laterally disposed portions respectively into contact with theopposite sides of an intermediate portion thereof, means for heating thefolded strips and means for longitudinally stretching said heated stripsto reduce the width thereof to a predetermined dimension uniformthroughout the length thereof.

12. Apparatus as in claim 11 wherein said slitting and scoring meanscomprises a pair of parallel, horizontally disposed shafts, a pluralityof slitting-scoring discs and spacer discs in alternating relation oneach of said shafts, each of said slitting-scoring discs having at leastone square peripheral edge, some of said slitting-scoring discs havingone beveled peripheral edge, the slitting-scoring References CitedUNITED STATES PATENTS 2,541,141 2/1951 Brandt 161107 2,985,503 5/1961Becker 264-147 XR ROBERT F. BURNETT, Primary Examiner R. O. LINKER, JR.,Assistant Examiner US. Cl. X.R.

